Two Outbreaks of Primarily Noninvasive Group A Streptococcal Disease in the Same Nursing Home, New York, 1991

Abstract

Group A Streptococcus has been identified as the cause of several outbreaks of infection in residents of nursing homes. These reports described outbreaks that included persons with severe invasive disease as well as more limited infection. The purpose of this report is to describe an investigation of two consecutive outbreaks of group A Streptococcus that occurred in a single nursing home, where all affected residents had disease of mild to moderate disease severity. This report focuses on the identification of risk factors for infection and describes the approach used to control the spread of infection in the nursing home.

Group A Streptococcal Disease in Long-Term Care Facilities: Descriptive Epidemiology and Potential Control Measures

“…Having frequent visitors was found to be a risk factor for carriage of the outbreak strain in a Georgia outbreak; however, review of concurrent invasive GAS cases in a larger Georgia population did not identify community infections caused by the outbreak strain [25]. Four other investigations that assessed the role of having frequent visitors did not find an association with elevated risk of disease or carriage [23,26,27,32].…”

“…The role of staff in initiating or propagating GAS infection outbreaks is supported in several other investigations, including 2 investigations in which immobilized, isolated patients appeared to serve as reservoirs of infection from which staff repeatedly recirculated the organism among other residents [24,29]. In multiple instances, investigators found that staff members with GAS pharyngitis had cared for case patients prior to the outbreaks [23,30,33], although isolates were not available to confirm that staff and patient cases were due to the same strains.…”

“…With a renewed focus on infection control, the second outbreak was successfully controlled [23]. In other outbreaks, 2 distinct GAS strains were found to be circulating in the home concurrently, indicating that GAS introduction had occurred through separate infection-control breaches on different occasions [20,26].…”

“…Most outbreaks occurred in the winter and spring, mirroring seasonal GAS infection patterns in the general population [21]. Outbreaks lasted from !1 month to nearly 1 year and varied greatly in tempo of outbreak progression; some evolved within weeks [19,[22][23][24][25][26], whereas others were characterized by intermittent occurrence of cases over several months [24,[27][28][29][30].…”

“…In most published investigations, all available LTCF staff were screened for GAS colonization, but several investigators only screened symptomatic staff or those staff closely linked to ill patients. Carriage of GAS among staff was identified in 9 of 12 investigations in which all staff members were screened; staff carriage rates were 2%-9% [22][23][24][25][26][27][28][29]32] (D.C.B., unpublished data). In 4 other outbreaks, only staff who were symptomatic or had close contact with case patients were screened; carriage was found in 2 of these outbreaks, occurring in 8% and 10% of screened staff [19,30,31,33].…”